This invention pertains generally to circularly cylindrical cavity power combiners for combining the power output of a plurality of diode oscillators and, in particular, to a combiner of such type wherein the number of diode oscillators combined may be doubled without increasing the outer diameter of the combiner.
It is known in the art (U.S. Pat. No. 3,931,587) that a microwave power source may be formed by providing a cylindrical cavity operating in the TM.sub.010 mode to combine the outputs of a plurality of coaxial diode oscillators. In such a source, coaxial diode oscillators are symmetrically disposed on the periphery of the cylindrical cavity. The number of coaxial diode oscillators which may be so disposed is limited by the length of such periphery with the result that the amount of microwave power out of such a combiner is similarly limited.
It is also known in the art (see U.S. Pat. No. 4,172,240) that the number of coaxial diode oscillators in a microwave power source may be doubled by positioning the coaxial diode oscillators in axially oriented holes around the periphery of both the top and bottom sections of a cylindrical cavity operating in the TM.sub.010 mode, with the associated stabilizing loads extending through radially oriented holes in the side walls of both the top and bottom sections of such cavity. Although the number of coaxial diode oscillators combined in a single cavity may be increased in this manner, extending the stabilizing loads radially outward from the cavity substantially increases the size of the combiner. If the combiner is to be utilized in a solid state transmitter for an active missile seeker, such increased size is obviously undesirable.
It is also known in the art (see U.S. Pat. No. 4,189,684) that the number of coaxial diode oscillators that may be combined in a single cavity combiner may be increased by increasing the length of the periphery of a cylindrical cavity to support the TM.sub.020 mode and by suppressing higher order modes.